let obj1 = {
  name: "张三",
  age: 12
}
let obj2 = {
  name: '李四',
  age: 20
}
Object.setPrototypeOf(obj1,obj2)
console.log(obj1.__proto__);
console.log(obj1.constructor.prototype);
console.log(Object.getPrototypeOf(obj1));